Motherboard - Brian Merchant
If every nation that has so far pledged to cut down on its carbon
emissions made good on its promises, the global average temperature
would still rise 3.5˚ Celsius by the end of the century. According to a new study from MIT Sloan and Climate Interactive,
even with the hard-won commitments from nations around the world, we’re
still on track for “catastrophic” levels of planetary heating. If, that
is, the governmental targets aren’t stepped up, or paired with other
aggressive efforts.
In advance of the upcoming climate talks in Paris this year,
which many consider the world’s best shot at cementing an agreement to
limit global warming, nations have begun submitting what are known in
UN-speak as Intended Nationally Determined Contributions (INDCs).
These
are basically declarations of intent for how a given country aims to
reduce or mitigate its carbon emissions—Norway, for instance, is pledging to reduce its carbon emissions by 40 percent by 2030. The US is aiming for a 28 percent CO2 reduction by 2025. China, meanwhile, again made waves
when it announced it would match the US’s fuel efficiency standards and
launch a new cap-and-trade system for reducing pollution as part of its
plan.
It should speak to the scope of the climate problem that
even with all those reduction commitments on the books, we’re headed for
what scientists say are civilization-threatening levels of warming. To
reach that conclusion, MIT rounded up all such pledges that are on the
books, and analyzed the total impact they’d have on temperature rise.
The
study concludes that the commitments, if fulfilled, will indeed make a
serious difference—they will prevent an entire 1˚C of temperature
rise—but that they won’t prevent the global thermostat from spiking past
2˚C; the benchmark that’s long been considered the threshold for
dangerous warming.
The breakdown, according to MIT and CI, looks roughly like this:
“Sea level rise of 1 meter or more would be expected by 2100, with
the possibility of destabilization of the Greenland and West Antarctic
ice sheets, which would cause much more sea level rise and flooding of
coastal communities.”
It’s a full-scale planetary disaster, basically.
Worst of all, of course, is business as usual. The
talks fail, there’s no treaty, and we go on burning fossil fuels like
it's 1999. That lands us at 4.5˚C, or 8.1˚F, worth of temperature rise
by the end of the century, if we maintain the status quo trajectory.
That’s also a nightmare scenario.
The World Bank, not exactly a liberal institution, did a report analyzing
the outcome of a 4˚C+ world: “4°C scenarios are potentially
devastating: the inundation of coastal cities; increasing risks for food
production potentially leading to higher under and malnutrition rates;
many dry regions becoming dryer, wet regions wetter; unprecedented heat
waves in many regions, especially in the tropics; substantially
exacerbated water scarcity in many regions; increased intensity of
tropical cyclones; and irreversible loss of biodiversity, including
coral reef systems.” More of the same, more of the worse.
Of course, some scientists say even 2˚C of warming would be a “disaster.”
But
it’s worth honing in on the silver lining here—1˚C worth of reductions,
the amount nations have already pledged to uphold—is a major
achievement, and a serious step forward from what has in the past been a
tortured, laborious, and unproductive negotiation process. There’s
reason to believe, with the costs of renewable power falling fast, and a
spirit of international cooperation slowly coalescing around the
climate problem, that a 2˚C target isn’t out of reach.
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